“[G]as flames, with their glowing carbon particles, were scarcely brighter than candle flames. One needed something additional, a material that would shine with special brilliance when heated ina gas flame. Such a substance was calcia—calcium oxide, or lime—which shone with an intense greenish white light when heated. This “limelight,” Uncle Dave said, was discovered in the 1820s and used to illuminate the stages in theaters for many decades—that was why we still talked about “the limelight,” even though we no longer used lime for incandescence.”

—Oliver Sacks, Uncle Tungsten: Memories of a Chemical Boyhood, 2001.